1. Field
Embodiments described herein relate generally to a position detecting apparatus and a driving system.
2. Background Art
As a means of position detection for a linear motor or the like, an arrangement is used in which a magnetic scale, an MR sensor (magnetic reluctance sensor) or the like operates in two phases. Such a position detecting arrangement incorporates a detector that uses the analog signal level of the MR sensor and means for counting the MR signal wave number to improve the resolution of the magnetic scale. In such an arrangement, however, a deviation among the amplitude levels of the analog signals and a direct-current offset cause a decrease of the position detection precision.
To overcome the problems, changes in amplitude and offset with temperature are compensated for. However, only an open loop control, such as compensation based on early learning or a coefficient, is conducted, and the accuracy of the amplitude of the signal is not assured.